Pyrrole filter and backing dye



Patented Oct. 13, 1942 PYRROLE FILTER AND BACKING DYE Company, New Jersey Rochester, N. Y., a corporation of Application February 7, 1940, Serial No. 317,726 in Great Britain February 17, 1939 I Claims.

This invention relates to improvements in photographic elements and more particularly in photographic elements having light screening substances therein.

-It is known that photographic elements require, for many purposes, to have light screening substances incorporated therein. screening substance may be in a layer overlying a light sensitive emulsion or overlying two or more light sensitive emulsions; or it may be in a light sensitive emulsion for the purpose of modifying a light record in such emulsion or of protecting an underlying light sensitive emulsion or emulsions from the action of light of wave length absorbed by such light screening substance; or it may be in a layer not containing a light sensitive substance but arranged between two light sensitive emulsions; or it may be in a layer serving as a backing on an element having one or more light sensitive emulsions (for example, to reduce halation.)

In particular, light screening substances are often required (a) in overcoatings upon photographic elements to protect the light sensitive emulsion or emulsions from the action of light which it is not desired to record, e. g. ultra-violet light in the case of still or moving pictures, especially color pictures, (b) in layers arranged between differentially color-sensitized emulsions, e. g. to protect redand green-sensitized emulsions from the action of blue light and (c) in backings, forming the so-called anti-halation layers, on either-side of a transparent support carrying the light-sensitive emulsion or emulsions. a

In most cases, and especially 'when the element contains a color-sensitized emulsion or colorsensitized emulsions, it is particularly desirable to employ light-screening substances which do not affect the general sensitivity or the color sensitivity of light-sensitive emulsions with which they may come into contact. It is also particularly desirable to employ light-screening substances which do not substantially diffuse from the layers or coatings in which they are incorporated, either during the manufacture of the element or on keeping it or in photographically processing it. Finally, it is generally necessary to employ light-screening substances which can readily be rendered ineffective, i. e. decolorised Such a light or destroyed and removed, prior to or during or after photographic processing; for many purposes it is particularly convenient to employ lightscreening substances which are rendered ineffective by one of the photographic baths employed in processing the element after exposure, e. g. a photographic developing bath or fixing bath or a silver-oxidizing (including silver-removing) bath. For example, in an element which is to be processed by reversaLitis often convenient to employ a light screening substance which is rendered ineffective by the developer employed to develop the latent image or images to silver since exposure to light of the residual light sensitive emulsion or emulsions may thereby be facilitated. This is particularly the case when, in making color photographs, several differentially colorsensitized emulsions, constituted, for example, by silver halide, such as silver bromide dispersed in gelatin, collodion or other colloid, are coated on one or both sides of a support, for example in inseparably-superimposed layers. Such difierentially color-sensitized emulsions have to be processed to difierent colors and to facilitate the differential color-processing, methods involving selective exposure of light sensitive images in the layers may be employed. Such selective re-exposure, e. g. of silver halide remaining undeveloped in development of the latent images formed in silver halide emulsion layers (residual silver halide) is often facilitated if the lightscreening substance .which was present during the original exposure is decolorized or removed in the developing bath employed to develop the latent images to silver. Any of the elements referred to above may be such that one or more of the emulsions contain coupling components, e. g. those described in French Patent 834,37l, granted August 16, 1938.

Numerous substances have been employed as light-screening substances for the purposes indicatedabove. Many of these are known yellow dyes but it is has proved extremely difficult to find dyes having the combination of qualities desired. Many are not resistant to difiusion and wander rather freely from the layer in which it is intended that they should remain; many adversely affeet the sensitivity of light sensitive emulsions with which they come into contact (a number of these reduce the general sensitivity or some specific color sensitivity thereof, but others of Jugated double lihka'ges -from the boiling mixture.

them may even impart an additional and unwanted specific color sensitivity thereto).

We have now found a class of dyes, members of which fulfill to a very satisfactory extent the requirements of light-screening substances for use in photographic elements. This class consists of polymethine dyes-derived from pyrrole orindole or from their substituted derivatives.

Such dyes may have a pyrrole nucleus or an indole nucleus (in either case containing substituents or not) linked to a heterocycllc nucleus containing a nitrogen atom either directly ,or

through an intermediate polymethine chain so .that in either case there is a chain, comprisscreening dyes have the following general. for- R where Z=the non-meta1lic atoms necessary to comple e a heterocyclic nucleus J =the non-metallic atoms necessary to. complete a pyrrole nucleus R=hydrogen, alkyl or a chemical bond of a pyridine ring R'=alkyl R"=hydrogen, alkyl, and or a chemical bond of the same pyridine ring as R =2 or 3 n=1 or 2 =an acid radical The general formula indicates that thecompounds may be depicted in two electromeric forms. Example 2.2 g. (1 mol.) 2-p-acetanilidovinylbenzoxazole I ethiodide, 2.4 g. (1 mol.+500%) N-methylpyrrole and cc. acetic anhydride were boiled 7 minutes with stirring in a test tube. Dye separated Chilled; filtered, washed with acetic anlrvdride and acetone and dried. Yield 1.7 g. The product appeared to be a mixture of unchanged starting .material and the desired dye. The dye was obtained fairly pure by, chilling the solution of the crude product in 50 cc. abs. EtOI-I for minutes, whereupon the dye separated as red crystals. The mixture was filtered as soon as yellow crystals started to separate. Yield .5 g., 26%. M. P. 264-2fi$ w h hrs.

decomposition. After a further recrystallization from abs. EtOH, (100 cc./g.) the product was obtained as red crystals melting with decomposition at265-267. v

5 Example 2 Hr (3-ethyl-2-benzoxazole)-(l-lauryl-2,5-dimeth dimethinecyanine iodide 4.34 g. (1 mol.) z-p-acetanilidovinylbenzoxazole ethiodide, 5.26 g. (l mol.+l00%)- l-lauryl- 2,5-dimethylp'yrrole and 20 cc. of acetic anhydride' were refluxed IO-minutes. The orange re action mixture was chilled, product filtered oil, washed with acetone and water and dried. Yield 4.4 g.,' 78%. After recrystallization from abs. EtOI-I, (10 cc./g.) the product was obtained as 206-207. Yield 3.7 g., 66%.

1-laur1 Z-2,5-dimethylpyrrole.--Prepared by the method of Lions et al. Proc. Royal Soc. New South Wales, 1937, 71, 92 from laurylamine. B. P. 152- l55 /2 mm. Yield 75%.

'1-lauryl-2,5-dimethyl 3 pyrrole aldehyde.- .52.6 g. (1 mol.) 1-lauryl-2,5-dimethylpyrrole, 36 g.. (l mol.+300%) formamide. 35 g. (1 mol.+l00%) PoCla and 200 cc. absolute ether .was allowed to stand at room-temperature for 24 The yellow $011 which separated was filtered oil, washed with abs. ether and dried. The solid was suspended in water, made alkaline with stirring and cooling, and the product filtered oil, washed with water and dried in vacuum dessicatorover CaClz.. Crude yield 40.0 g., 69%.

After recrystallization from pet. ether the product was obtained as nearly colorless crystals melting at 60-61.

Example 3 czHs- 803671111 1:75 g. (1 mol.) 2-methylbenz othiazole-etho-ptoluenesulfonate, 1.46 g. (1 mol.) 1-lau'ryl-2.5-.

dimethyl-3-pyrrole aldehyde and 10 cc. of acetic anhydride were refluxed 5 minutes. The orange reaction mixture was chilled, diluted with 50 cc. ofether and the product filtered ofl. The red 0 crystals were washed with acetone and water and dried. Yield 1.5 g., 48%. After recrystallization from abs. EtOH, (28 c'c./g.) the product was obtained as vermillion crystals melting with decomposition at 181-1822 Example 4 7o -c1sc=cH---I v CE: SOzC7H1 CHILNJCHa cnxcnomcm 7 l-methyl-Zfi-quinoline) (1 -lauryl-2,5- dimethyl -3- pyrrole) imethinecyaninep-toluenesulfonate orange crystals melting withfldecomposltion at v Example 3-I(3-ethyi-2(3)-benzoxszolylldene) ethyiidenel-Z-methyl-indoienine hydro-iodide V 2.2 g. (1 mol.) 2-fi-acetanilidovinyibenzoxazole ethiodide, 2.6 g. (l moi-+1.02%) a-methyliiidole and ,10 cc. of acetic anhydride were boiled 3 minutes in a test tube. Dye separated from the boiling solution. Chilled, filtered, washed with water and acetone and dried. Yield 1.4 g., 55%.

After recrystallization from MeOH, (120 cc./g.) the product was obtained as brown needles with metallic reflex melting with decomposition at 287-288. Yield 1.25 g., 58%.

Example 6 :Hn 3[(3-ethyl-2(3)-benzothiazoiyiidenei ethyiidene]-2 methyiindolenine hydro-iodide 2.25 g. (1 mol.) 2-p-acetaniiidovinylbenzothlazoie ethiodide, 2.6 g. (1 moi.+100%) a-methyir indole and cc. of acetic anhydride were refluxed 5 minutes. The orange solution was chilled, filtered, the dye washed with acetone and water and dried. Yield 1.8 g., 81%. After recrystallization from MeOI-I, (200 cc./ g.) the product was obtained as minute red crystals with metallic reflex melting with decomposition at Example 7 2H5 (3-ethyi-2-benzoxazole)-(l-ethyl-3 indoie)-dl-methincyanine iodide 22 g. (1 moi.) 2-fi-acetanilidovinylbenzoxazole ethlodide, 1.5 g. (1 mol.+100%) l-ethylindole and 10 cc. acetic anhydride were boiled in a test tube for 5 minu The orange solution was chilled, filtered. the dye washed with acetone and water and dried. The product appeared to be a mixture of the desired dye with unchanged starting materials Wt. 1.8 g. This was extracted with EtOI-I and the dye isolated from the more soluble fraction as orange-red crystals. Yield .3 g., 14%. After recrystallization from abs. EtOH the dye melted at 247249 with decomposition. Yield .25 3., 11%. j

- cc./g.) the product Example 8 0\ /C=CH--CH=-" CaHu- N zHs H I 3-l(3ethyl-2(3)-benzoxazolylidene) ethylldene1-2hexylindolenine hydro-iodide 4.34 g. (1 mol.) 2-p-acetanilidoviny1benzoxazole ethiodide, 2.7 g. (1 m0l.+35%) 2-hexylindoie and 15 cc. of acetic anhydride were refluxed 5 minutes. Dye separated from the boiling solution. Chilled, filtered, washed with acetone and water and dried. Yield 2.8 g., 56%. After recrystallization from MeOI-I the product was obtained as minute brown crystals with metallic reflex melting with decomposition at 272-274. Yield 1.4 g., 28%.

Me N

(3-ethyi-2-benzoxazoie)-(IQ-dimgiggidindole) dimethinecyanine .87 g. (1 mol.) 1,2-dimethyl-3-indolealdelryde, 1.45 g. (1 mol.) Z-methylbenzoxazole ethiodide and 10 cc. acetic anhydride were refluxed 5 minutes. Orange coloration. Solid dye separated from the boiling reaction mixture. Chilled, filtered, washed with-water. and acetone and dried. Yield of brownish yellow crystals 2.15 5., 97%. After recrystallization from MeOH (50 was obtained as orange crystais melting with decomposition at 264-265. Yield 2.0 g., MeOH solution yellow.

Example 10 (3-ethyl-2-benzoxazole)-(2,5'dimethyi-l-phenyl-Ztpyrrole) dimethinecyaniue iodide 4.35 g., (1 mol.) Z-fl-acetaniiidovinylbenzoxazole ethiodide, 6.0 g. (l mol.+300%) 2,5-dimethylrl-phenylpyrrole and 25 cc. acetic anhydride were refluxed 15 minutes. The orange mixture was chilled, filtered, product washed with water and acetone and dried. Brown crystals. Yield 2.7 g. 57%. After recrystallization from MeOI-I, (15 cc./g.) the dye was obtained as light brown crystals melting with decomposition at 214- 220. Yield 1.6 g., 34%. After three further crystallizations from abs. EtOH with Norite the M. P. was constant at 249251 dec. MeOH solution yellow.

Example 11 Aeuzyi (l-benzyl-2,6-dimsthyl-3-pyrroie)-(3-ethyl-2-benzoxazoie) dimethinecyauine iodide 4.34 g. (1 mol.) Z-B-acetanilidovinylbenzoxazole =ethiodlde, 3.7 g. (1 mol.+100%) l -benzyl-2,5-

dimethylpyrrole and 15 cc. acetic anhydride were refluxed for 10 minutes. Brownish orange coloration. Chilled, filtered, washed with acetone and water and dried. Yield of brown crystals 3.1 g.,

64%. After recrystallization from abs. EtOH,

(20 cc./g.) the product was obtained as granular brown crystals melting with decomposition at 219- 221". Yield 2.0 g., 41%. MeOH solution yellow.

Example 12 4.34 g. (1 mol.) 2-p-acetanilidovinylbenzoxazole ethiodide, 4.0 g. (1 mol.+100%) 2,5-dimethyl-1- p-methoxy-phenylpyrrole and 15 cc. acetic anhydride were refluxed 15 minutes. Orange coloration. Chilled, filtered, washed with acetone and water and dried. Brown crystals. Yield 2.5 g.,

50%. After recrystallization from abs. EtOH,-

(11 cc./g.) the product was obtained as granular brown crystals melting with decomposition at 214- Yield 1.9 g., 38%. MeOH solution yellow.

Example 13 Me NJMe I (eetyl and octadecyl mixture) ethinecyanine iodide 4.34 g. (1 mol.) 2-fi-acetanilidovinylbenzoxazolek ethiodide, 6.4 g. (1 mol.+100%) mixture of'lcetyl-2,5-dimethylpyrrole and 1-octadecyl-2,5-dimethylpyrrole and 20 cc. acetic anhydride were refluxed minutes. Chilled, filtered, washed with acetone and water and dried. Brown crystals. Yield 4.1 g., 66%. After recrystallization from abs. EtOH (5 cc./g.)" the product was obtained as brown needles melting with decomposition at 180-183. yellow.

Example 14 N(Me) 1- di th 1 f 2.ii.35%;?lldfidligilliiii. "4.34 g. (1 mol.) 2-p-acetanilidovinylbenzoxazole ethiodide, 4.3 g. (1 mol. 100%) 1-p-dimethylaminophenyl-2,5-dimethyl pyrrole and Yield 3.7 g., 60%. MeOH solution p-hydroxyethobromide, 5 drops piperidine and 15 '25 lution yellow.

' Example 15 s [l MU i Br I Lauryl HOCH: H:

(3-B-hydro ethyl-2-benzothiazole)- l-lau l-2,5-dimethylgpyrrole) dimetliinecy e brg mide 2.9 g. (1 mol.) 1-lauryl-2,5-dimethyl-3-pyrrolealdehyde, 2.74 g. (1 mol.) 2-methyl-benzothiazol'ecc. abs. EtOH were refluxed 10' minutes. Orange coloration. Chilled, filtered, washed with acetone and water and dried. Yield of yellow crystals 4.05 -g., 73%. After recrystallization from abs. EtOH, (10 cc./g.) the product was obtained as brownish orange crystals melting with decomposition at 234-235". Yield 3.6 g,,*66%. MeOH s0- Example 16 C CH=CHC O I N l C.H; =CH Et I (3-ethyl-2-benzoxazole)-(2-phenyl$g1yrrocoline) dlmethinecyanine 1.93 g. (1 mol.) 2-phenylpyrrocoline, 4.34 g. (1 mol.) 2-fl-acetanilidovinyl-benzoxazole ethiodide and 25 cc. glacial acetic acid were refluxed 10 minutes. Red coloration. Chilled, -flltered, washed with acetone and water and dried. Yield of red crystals 4.45 g., 91%. Afterrecrystallization from abs. EtOH, (19 cc./g.) theproduct was obtained as granular red crystals melting with decomposition at 204-205".

Yield 3.9 g,, 79%. MeOH solution orange.

Example 17 I (3-ethyl-2-benzoxazole)-(2-methyl-l-pyrroooline) dimethinecyaniue iodide O 4.34 g. (1 mol.) 2-p-acetanilidoyinylbenzoxazole ,ethiodide, 1.3 g. (1 mol.) 2-methylpyrrocoline and 15 cc. glacial acetic acid were refluxed 5 minutes. Red coloration. Chilled, filtered, washed with acetone and water and dried. Yield of green crystals 3.85 g., After recrystallization from MeOH, (39' cc./g.) the dve was obtained as green crystals with a golden reflex melting with decomposition at 245-246. Yield'3.2 g., 75%.

MeOH solution orange.

2,298,731 Example 18 Ezvample 21 c-cn=on C-CH=CH--CO0Et N M Me N Me Me N N Et I I Et 1 I CHr-CHPOMB H (3-ethyl-2-benzoxazole2i (1-8-methoryethyl-2,5-dimethyl-3-pyrrole)- imethinecyanine iodide Example 19 (3-ethyl-2-benzoxazole)-(2,fi-dirnethyl-l-tetra-l rdrofuriuryl- 3-pyrrole) dimethinecyanine iodoic ace g. (1 mol.) 2-p-acetanilidovinylbenzoxazole ethiodide, 3.6 g. (1 mol.+100%) 2,5-dimethyll-tetrahydro furfurylpyrrole and 25 cc. acetic anhydride were refluxed minutes. Brownish orange coloration. Chilled, filtered, washed with acetone and water and dried. Yield 3.8 g., 79%.:

After recrystallization from MeOH, (24 cc./g.) the dye was obtained as brown crystals melting with decomposition at 250-251. Yield 3.35 g., 70%. MeOH solution yellow.

Example 20 1 c-cr=cH- MeLJMe (Byclohexyl (aethyl-2-b:nzoxazole)-(l-cyclohexyl-2,5:dimethyl-3-pyrrole) J dlmethinecyamne iodide (3-carbethoxy-2,5-dimethyl-4pyrrole)-(3-ethyl-2-benzoxezole) dunethinecyanine iodide 5.8 g. (1 mol.) 2-methylbenzoxazole' ethiodide, 3,9 g. (1 mol.) 3-carbethoxy-2,5-dimethyl-4- pyrrolealdehyde, 5 drops piperidine and 30 cc. n-propylalcohol were refluxed minutes. Orange coloration. Chilled, filtered, washed with acetone and water and dried. Yield of yellow crystals 2.55 g., 27%. After recrystallization ethiodide, 1.5 g.

' 4.34 g. (1 mol.) 2-p-acetanilidovinylbenzoxazole ethlodlde, 3.54 g. (1 mol.+l00%) l -cyclohexyl-2,5-dimethylpyrrole and 25 cc. acetic anhydrlde were refluxed 10 minutes. Orange coloration. Chilled, dye pptd with 100 cc. ether, ether decanted of: and residue stirred with 10 cc. acetone until crystalline. Filtered, washed with acetone and water end g., 45%. After recrystallization from abs. EtOH, (13 ccJg.) the dye was obtained as orange needles melting with decomposition at 250-252. Yield 2.0 g., 42%. MeOH solution yellow. L

dried. Yield 2.25

from abs. EtOH, (12 cc./g.) the dye was obtained as yellow crystals melting with decomposition at 226227. Yield 1.? g., 18%. NieOl-I solution yellow.

Example 22 (3-ethyl-2-benzoxazole)-(2,3-dimethyl-1-pyrrocoline) dimethinecyenine iodide 4.34 g. (1 mol.) 2-p-acetanilidovinylbenzoxazole (1 mol.) 2,3-dimethylpyrrocoline and 25 cc. glacial acetic acid were refluxed 5 minutes. Red coloration. Chilled, stirred until crystalline, again chilled and filtered. Washed with acetone and water and dried. Yield of dark red crystals 3.85 g., 87%. After recrystallization from MeOl-l, (42 c'c./g.) the dye was obtained as greenish-red needles with green-reflex melting with decomposition at 266-267". Yield 3.55 g., MeOH solution orange.

Example 23 Lauryl (l-lauryl-2,5-dlmethyl-3'pyrrole)-(1,3,3-trimethyl-2-indole) dimethinecyenine iodide lization from abs. EtOH, (B ed/g.) the dye was obtained as bright red flakes melting with decomposition at 283-285"; Yield 2.0 g., MeOH solution orange.

acetic acid were refluxed 3 minutes. Blue color- 3 e [4 (3 ethyl 2(3) benzothiazolylidene) 2 butenylidene] 2 methylindolcnine hydrobromide 2.6 gra ns (1 mol.) 2-(4-acetanilido-L3-butadienyl) -benzothiazole ethiodide, 1.3 grams (1 mol.+100%) u-methylindole and cc. acetic Example (3-ethyl-2-benzothiazole)-(2-phenyl-1 pyrroeo1ine) tetramethine cyanine chloride 4.8 grams (1 mol.) 2-(4-acetanilido-L3-butadienyl) benzothiazole ethiodide, 1.93 grams (1- mol.) 2-phenyl-pyrrocoline, and 30 cc. glacial 4o 'ationand green crystals of dye separated at 'once' from the boiling mixture. Chilled, filtered,

washed with'acetone and water and dried. Yield 2.6 grams, 49%. The product was extracted with 700 cc. boiling CHaOH. Residue of green crystals 1.3 grams, M. P. 257-259; The solution was chilled and yielded .65 gram green needles, M. P. 257-259 side by side with above. Combined Yield 37%. The dye was converted to chloride in cc. cresol solution using excess freshly precipitated silver chloride. The mixture was stirred mechanically for 15 hours at 100, filtered hot and chilled. Diluted to 400 -cc. with ether and chilled overnight. The green crystals which separated were filtered off, washed withether and acetone and dried. Yield 1.6 grams, 36%. After recrystallization from absolute EtOH, (15 cc./g.)

the product was obtained as green needles with bronze reflex melting at 85-86, yield 1.3 grams,- 30%. CHaOH solution bluish-r Example 26 (3 ethyl-2-benzoxazole) (2-methyl-l-pyn'ocoline)-tetramethinecyanine iodide were refluxed 5 minutes. Blue coloration. Green crystals separated ture. Yield 2.9 grams, 64%. Disso boiling mix-.

at once from thg ved in 50 cc.

cresol (m and p mixture) heated to filter- 7 ed hot, cooled and diluted with 250 cc. CHaOH.

Green crystals separated on chilling. Filtered,

washed with CHaOH and dried. Yield 1.95 grams,

i 43%, M. P. 247-250 (3 ethyl -t2- benzothia e dec. CHaOH solution blue. Example 27 zole) (2,3-dimethyl-1-pyrrocoline)- tramethinecyanine-p-toluenesulfonate 4.9 grams (1 mol.) 2(4-acetanilido-L3-butadienyl) benzothiazole etho-p-toluenesul-fonate, 1.45 grams (1 mol.) 2,3-dimethylpyrrocoline and 25 cc. glacial acetic acid were refluxed 5'. The blue solution was cooled, diluted with 50 cc. acetone and 100 cc, ether and chilled. The dye which separated was filtered oif, washed with ether, acetone and water and dried. Yield of green crystals, 2.3 grams, 43%. After recrystallization from MeOH (32 cc./g.) the product was obtained as bright green crystals melting with decomposition at 272-273". blue in MeOI-I.

In the present Yield 2.0g., 38%. Solution specification we refer to dyes containing a "pyrrole nucleus. lIt is to be understood that by this term we intend to include dyes derived from both pyrrole and indole, the indole nucleus being considered a substituted pyrrole, and the I generic to both pyrrole and indoleterm pyrrole nucleus being While we reterin the claims to dyes containing a pyrrole nucleus, we intend to include both pyrrole and indole dyes.

For the preparation of overcoating layers, filter layers and anti-halation layers, according to our invention, from 50 mg. to mg. or dye are dissolved in from 2 'to 5 cc. of a water-miscible solvent. Methanol or acetone are suitable for this purpose but pyridine or Cellosolve may also be used. The solution is then added to about-25 mixture coated on be converted into cc. of a 5% gelatin solution at 40 C. and the the support. 11' the dye is too may conveniently the chloride, using cresol as a solvent for the conversion.

graphic elements As shown in Fig. material such as acetate, synthetic In the accompanying drawing, the various figures are enlarged section views of photohaving filter layers and antihalation layers made according to our invention.

l a support III of any suitable cellulose nitrate or cellulose resinous material, or opaque material such as paper is coated with an emulsion layer II and an overcoating layer l2 containing apyrrole' polymethine invention.

dye according to our Fig. 2 illustrates a multi-layer photographic element for color photography in which the support 10 is coated. with sensitive layers l3, l4

0 and I! which record respectively the red, greenand blue regions of the'spectrum. Between the emulsion layers l3 l6 containing a red between the layers containing a yell serve purposes well known in color photography of preventing exposure of a lower layer of the element by light which the filter layers absorb. The pyrrole polymethine dyes used may also absorb light in other regions, such as ultra-violet light.

Fig. 3 represents a film having an anti-halation layer containing a pyrrole polymethine dye according to our invention. As shown therein, the support to contains an emulsion layer H on one side and an anti-halation layer l8 containing the pyrrole dye on the opposite side.

Our invention is not limited to the examples included in the present specification but any compounds coming within the scope of the in- These filter layers vention may be used. The dyes may be dis-' persed in gelatin, collodion, gum arabic, synthetic resins or other suitable colloid or they may be dispersed in photographic emulsions such as gelatino silver halide emulsions and may be coated in any suitable manner.

It is to be understood that our invention is limited only by the scope of the appended claims.

We claim:

1. A photographic element comprising a sensitive layer and a light absorbing layer containing a. dye having the following formula:

in which Z=the non-metallic atoms necessary to complete a heterocyclic nucleus; J =the nonmetallic atoms necessary to complete a pyrrole nucleus; R=hydrogen, alkyl, or a chemical bond of a pyridine ring; R=alkyl; R"=hydrogen, alkyl, aryl, or a chemical bond of the same pyridine ring as R; d=a positive integer of from 2 to 3; n==a positive integer of from 1 to 2; and X=an acid radical.

2. A sensitive photographic element comprising a filter layer containing a dye having the general formula expressed in claim 1.

3. A sensitive photographic element comprising a filter layer containing a (3-alkyl-2-benzoxazole) (ii-pyrrole) dimethinecyanine salt.

'4. A sensitive photographic element comprising a, filter layer containing a (3-a1kyI 2-benzothiazole) (ii-pyrrole) dimethinecyanine salt.

5. A sensitive photographic element comprising a filter layer containing a (3-alkyl-2-benzoxazole) (1 lauryl 2 ,5 dimethyl 3 pyrrole) dimethinecyanine salt.

LESLIE G. S. BROOKER. ROBERT H. SPRAGUE. 

